Interchangeable tooth



Patented Jan. 11, 1927. y

UITEB STATES EDXVARD 1?. CRESSLER, OF NEWTON', KANSAS.

` INTERCHANGEABLE TOOTH.

. Application filed lfay 10,

This invention relates to artificial teeth and has reference more particularly to the manner of connecting or interlocking the tooth facing or body, with the backing or retaining member, more especiallly for `bridge or crown work, to produceV an interchangeable tooth.

One object of the invention is to so form the interlocking connecting parts, that the tooth facing will be properly positioned and centered on the backing, and will be securely held thereon Without liability of shifting or displacement.

Another object of the invention is Vto produce in an interlocking tooth, a root tip or gum tip effect, to adapt the tooth for use in cases of recent extraction, or in cases where' the gum has receded after extraction.

A furth-er object ofthe invention is to so form the connecting means for interlock-v ing the tooth facing with its backing or retaining member, that a new facing may be readily interchanged for a broken facing, and may be applied to vthe backing horizontally face on without sliding it vertically into place, and thereafter secured firmly in position,

Another object of the invention is to produce in an interlocking tooth, an incisal edge effect to adapt the tooth for use in cases where esthetic appearance is desired.

With these and other objects in view, my invention consists of the construction and arrangement of the parts to be fully described in the specification to follow, and the novel features of which will be set forth in the appended claims.

My invention is susceptible'of many different forms of embodiment, and in the accompanying drawings I have illustrated a number of such embodiments by way of example, showing the invention applied t-o both anterior and posterior teeth, more particularly for bridge and crown work; It will be manifest however to those skilled in the art, that the invention is not limited to bridge and crown work, but is Vapplicable also to denture or plate work; and 'further it will be understoodthat the invention is not limited to any particular form or construct-ion of the parts, except in so far as such limitations are specified in the claims.

In the accompanying drawings: f

Fig. 1 is a side elevation, partly in section, of a tooth of anterior form having my invention applied thereto in one form.

1923. f serial No. 637,948.

Fig. 2 is a similar View showing the invention in slightly different form.

Fig. 3 lis a perspective view of the retaining member or backing of the form of Fim 1, the same being separated fromthe tooth facing.

F ig. 4t is a rear elevation of a tooth facing of the form shown in Fig. l, showing the same recessed to receive the backing of Fig. 3.

Fig. 5 is a side elevation, partly in section, of a tooth of posterior form having a retaining member or backing thereon of substantially the form shown in Fig. 2.

Fig. 6 is a view similar to Fig. 5 showing the invention in modified form.

Fig. 7. is a perspective view of the retaining member or backing of the form shown in Fig. 6, the same being separated from the toot-h facing.

Fig. 8 is a side elevation, partly in section, of a tooth of anterior form having my invention applied in still another form.

Fig. 9 is a perspective view of the backing or retaining member shown in Fig. 8, the same being separated from the tooth facing. f

Fig. 10 is a side elevation, partly in section, ofa tooth facing of anterior form having my invention applied thereto in still another modified form.

Fig. 11 is a perspective view of the retaining member shown in Fig. 10.

Fig. 12 is a sectional elevation of a tooth facing of posterior form having my invention applied thereto in still another modified form. l

Fig.V 13 is a perspective view of the retaining member of Fig. 12, separated from the facing.

Fig. 1li shows a number of fragmentary views of the incisal end of the tooth, showing diiferent formsof the terminal portions of the backing plates.

Y .Referring to the drawings:

Referring to Figs. 1, 3 and t, 1 designates a tooth body or facing of suitable material, preferably porcelain, in this inst-ance of anterior form, and 2 designates a retaining member or backing which seats against therear side of the tooth facing and is interlocked therewith. rlihc retaining member in this form of my invention, consists of a flat plate a having at its edge a rearwardly projecting flange 5, and a semi-circular positioning or centering block 6 fixed to the plate,

from which bloclr two diverging retaining pins 7 and 8 extend. The rear face of the tooth facing is formed with a flat surface 9 against which the plate seats, is also formed with a shoulder 10 near its incisal end to receive the flange 5, and is further provided with a semi-circular cavity or centering recess 11 to receive the positioning or centering block, and is provided also with two holes 12 and 13 to receive respectively the retaining pins 7 and 8, which latter are cemented in the holes to secure the facing firmly to the retaining member.

rlhe retaining pins may be of different forms and may be secured to the positioning block in different ways. in this particular form of the invention, the pin 8 is rigidly fastened to the bloclnwhile the pin 7 is pivoted thereto on an axis transverse to the axis of the pin, the pivot being formed by means of a lateral stud or journal lll on the inner end of the pin, which seats in a bearing opening formed in the edge of the block, so that the pin can be detached from the blocl: by shifting the journal endwise from its bearing opening. The pin is held from escape when swung outwardly to operative position as shown in Fig. l, by means of a notch 15 in the edge of the block in which the pin rests when swung outwardly. The mount-ing of the retaining pin pivotally on the block, enables the pins to be entered in the holes in the tooth facing when the latte1 is applied to the retaining member, notwithstanding the inclinedor diverging disposition of the holes.

ln Fig. 2 the construction is the same as that just described, except that the retaining pins 7a and 8'Lm are flexible, and consist each of a length of wire coiled in such manner as to give the pins sufficient stiffness to hold the facing to the retaining member, yet will be sufficiently flexible to enable the pins to be flexed to enter the diverging holes in the facino.

In 5, which shows my invention applied to a tooth facing of posterior form, the retaining member is the same as that shown in Fig. 2, except that in this case the pin 7b is fixed to the positioning block, and the pin 8b is flexible, similar to the flexible pins of Fig. 2.

A retaining member of the specific form described above, with the semi-circular positioning or centering block and the diverging retaining pins, insures a firm and secure interlocking connection between the facing and the retaining member, the positioning block acting to center and position the facing properly, and acting to effectually prevent the latter from shifting out of its proper osition on the backing plate; and while have shown the positioning block extending longitudinally of the tooth axis, it will be obvious that it may be extended laterally thereof or at intermediate angles, without departing from the spirit of the invention. By disposing the retaining pins at an angle with respect to the plane of the backing plate, with the two pins diverging from each other, they will act to most effectually hold the facing to the retaining member, and will resist to a maximun'i extent any tendency of the facing to separate therefrom. lt will be observed that the centering recess 1l above described is formed with upper and lower walls and with side walls. ln other words the recess is bounded by four walls, so that when the centering block is seated in the recess it will be prevented from shifting in any direction inthe plane of the tooth facing, and the recess will thus serve to position and retain the block with a true centering effect.

Referring to Figs. G and 7, these show an- "V other form of the retaining member embodying my invention. ln this case the diverging retaining pins 7 and 8c are formed on the ends of an arcuate rod 17 which seats in an arcuate tubular member 18 fixed to the outer side of the backing plate 4C, the ends of the tubular member being disposed around holes in the plate, through which holes the retaining pins extend, and the arcuate rod being provided at its junction with the pins, with shoulders which seat against the outer face of the plate. rl`he pins are in this instance formed of coiled wire as in the previous instance described, to make them flexibler but they may be pivoted to the ends of the arcuate rod, or one may be pivoted and the other fixed.

In Figs. 8 and 9 the retaining member is shown in still another form. ln these figures it will be seen that the diverging retaining pins 7d and 8d are in the form of spring' arms connected at their inner ends to the backing plate l and crossing each other so as to extend at diverging angles at their outer extremities.

ln Figs. 10 and 11 a form of retaining -member is shown in which the retaining pins 7e and 8e are connected at their inner ends directly with the backing plate 4e, the said pins, as in the previous instances described, extending at diverging angles with respect to each other,and with respect to thel plane of the plate. ln this case the pin Se is fixed rigidly to the plate, while the pin 7e is flexible, and in the form of a length of coiled wire as in certain other instances described.

In Figs. 12 and 13 the positioning block is omitted and the backing plate 4f is'bent on itself to form a transverse rib 19 which is seated in a transverse slot or recess formed in the rear side of the tooth facing,

which in this instance is of posterior form.4

There is but a single retaining pin 8f in this case, which extends from the edge of the rib and seats in a hole 1n the facing. in

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I this 'construction the rib on the backing plate acts to position the facing, and in connection with the retaining pin, insures a firm and fixed connection of the tooth facing to the retaining member.

In the various forms of the invention as above set forth, the edge of the backing plate terminates short of the incisal edge of the tooth facing, and various forms of terminal edges of the plates are shown. In Fig.v 141 at A, B and C, I show other forms of the terminal ends of the plates, and at D, the plate is shown as extending to and across the incisal edge of the tooth facing, in order to further strengthen the same and resist wear on the incisal edge of the same.

I propose to provide the tooth facing with a gingival tip portion, and this tip portion may be colored, pink for instance to simulate the appearance of the gum and thus constitute a gum tip, or it may be' left uncolored to simulate the root, and thus constitute a root tip. In Figs. 1, 4, 8 and 12 this tip portion has been shaded to indicate the coloring, while in Figs. 2, 5 and 6 it has been left uncolored. In the use of my invention in lcases of recent extraction or where there is a slight recession of the gum, a tooth facing with the uncolored tip would be employed; while in cases where the gum has receded substantially after extraction, a facing with a colored tip would be employed to simulate the gum. In this connection I believe myself to be the first to provide an interchangeable tooth with a gingival tip, either colored to simulate the gums or uncolored to simulate the root. It will be understood that in the use of a toothfacing of the form shown in Figs. 1, 2 and 8, the gingival colored gum tip will slightly overlap the edge of the natural gum, the rear face of the tip being shaped as shown to conform to the gum proper. Also it will be understood that in the use of a tooth facing of the form shown vfor instance in Figs. 5, 6, 10 and 12, the gingival root tip will extend only a slight distance into the socket in the natural gum, so as to just overlap the terminal edge of the gum, the said tip being colored as shown in Figs. 1 and 12 when excess recession of the gum has taken place, and being left uncolored as shown in Figs. 5, 6 and 10 when there has been very little if any recession of the gum.

By the provision of a tooth which is interchangeable and With a gingival tip portion to serve as a root tip or gum tip in the manner above set forth, it is possible to take care of irregularities which occur in the gum line due to the different degrees of recession at different'points. The teeth by being interchangeable and independent of each other, will have their gingival tips colored or uncolored independently, so that while certain v of them may for instance be uncolored when there has been nosubstantial or a very little recession of the gum, others may be colored to' simulate the gum when located at a point where excess recession has taken place. In other words a line of interchangeable teeth may be built up, where the edge o-f the gum is irregular dependent upon the degree of recession at different points, and the individual teeth provided with colored or uncolored gingival tips according to the condition of the gum at the position o-f the teeth in the row. In this way an irregular line of the gum may by the treatment of the tips of the individual interchangeable teeth in accordance with my invention, be made to appear regular, uncolored tips being employed where little or no recession has taken place, and colored tips being employed where excess recession has taken place.

In respect to the different forms of the invention above described, the backs of the tooth niembers or facings are ground to approximately the same angle of inclination, and the semi-circular recesses in the tooth facings, and the bores or holes for the re.- taining pins, are disposed at the same. angles and locations with respect to the rear faces of the facings. Likewise all the retaining members are made on approximately the same planes, with the retaining pins'attached at approximately the same angles with. relation to the planes of the retaining members. Similar teeth are therefore truly interchangeable, and the interlocking parts standardized, so that replacements may be readily made without re-shaping or reconstruction of the parts.

Having thus described my invention, what I claim is: Y

1. In combination with a tooth facing formed with holes extending in angular relation to each other, a backing plate adapted to be applied to the .tooth facing, and retaining pins carried by the plate to seat in said holes, one of said pins being movably connected with the plate.

2. In an interchangeable tooth, thecombination with a tooth facing formed with diverging holes therein, of a backing plate adapted to be applied to the tooth facing,

and retaining pins connected with the plate,

one of said pins being yieldable to permit the pins to seat in said holes.

3. In combination with a tooth facing formed with diverging holes therein, a backing plate adapte-d to be applied to the facing, and diverging retaining pins carried by the plate to seat in the holes, one of said pins having pivotal connection with the plate.

' 4C. In combination with a tooth facing formed with a centering recess therein hav ing upper and lower and side walls, said facing having a hole projecting forwardly from the recess, a backing plate having a projecting por-tion adapted to venter the recess and center the plate and having a reta-in* ing pin extending at :a-n angle to the direction of assembly of the facing and backing and yielclable :to enter the hole.

5. In combination with a tooth facing provided With a centering recess therein and provided also with holes Whose axes are Clisposed at an angle to each other, a backing plate adapted to seat .against the rear side of` 10 the facing, a `bloc-k :on the vbacking :pl-ate adapted to seat in the recess .and .center fthe plate,` and retaining pins on the block, Aone of said pins being yieldable to permit the pins to seat in the holes.

In testimony whereof I :hereunto hand this 25th yday of April, 1923.

EDWARD P. GRESSLER.

set my 

